A shelter in place health advisory was lifted Monday morning after a fire at a Redwood City recycling facility caused a heavy plume of smoke throughout three counties of the Bay Area.

You could notice the smell of burning plastic still in the air Monday night. It was continuing fallout from Sunday's fire at a peninsula recycling plant. It was a completely different scene, 24 hours later. There were no flames, no smoke, but there were still plenty of questions.

There was the good news along Seaport Boulevard in Redwood City. On Monday four joggers, out for their lunchtime exercise, gulping air were none the worse for wear. However, the air was still not perfect.

"You can tell something was burned or was burning previously," said Tony Fernandez, a jogger.

He could smell the remnants of a massive fire inside the Sims Metal Management Yard. Twenty four hours ago piles of scrap metal were on fire and heavy smoke blanketed the area, due to an inversion layer that kept it down.

"It got concentrated and it didn't move," said Lisa Fasano from the Bay Area Air Quality Management District.

The smoke was so thick that county agencies ordered residents to shelter in place. Concentrated amounts spread as far south as San Jose and it was a cloud that one air quality official described as, "a witches brew of toxic materials."

The legal standard for 24 hours is 35 parts per billion. For one hour, alone on Sunday the particulate matter reached a level of 114 and it wasn't the first from this plant.

"This is probably the largest. The other fires were very similar," said firefighter Ryan Ward on Sunday.

Sims has had previous violations.

"This particular facility experienced violations in 2007, air quality violations. I don't know what they have experienced since then, but it is a very dirty business," said Fasano.

It took 50 fire fighters almost six hours to contain the blaze and many remained overnight. There was no direct comment from Sims on Monday other than just a statement released through the company's PR agency in New York City. It said, "Sims Metal Management takes every incident of this nature seriously. We... engage in regular fire prevention training, and inspect our facilities on an ongoing basis."

The cause of the fire is unknown for now. The Redwood City Fire Department says it's under investigation.